Patent GB-359528-A (GB)
Title: Improvements in or relating to web controlling mechanism for printing or other machines
IPC: B65H23/08
Filed: 1930-07-19
Abstract: 359,528. Feeding webs. GOSS PRINTING PRESS CO., 1535, South Paulina Street, Chicago, U.S.A.- (Assignees of Fankboner, H.; 1535, South Paulina Street, Chicago, U.S.A.) July 19, 1930, No. 21912. Convention date, Dec. 4, 1929. [Class 100 (i).] In a web-roll braking device for a printing or other machine in which the brake is controlled by a pilot roller in engagement with the web, the brake comprises one or more friction belts engaging the roll surface and the pilot roller is adapted to energize an electric motor to adjust the pressure of the belts when there is a large variation of web tension, but under small variations of tension, is adapted to act directly upon the belts to effect their adjustment. In one form, Figs. 1 and 5, the web roll 10 is engaged by a number of narrow brake belts 50 of leather, textile fabric, or metal, secured at their lower ends to rollers 52 fixed to a shaft 81 and at their upper ends, through turnbuckles 55, to a shaft 54 carried by bell-crank levers 56. These bell-crank levers are also connected by links 75 to levers 72 having slotted ends 70 engaging the shaft of a slidable spring-mounted pilot roller 65 about which the web passes, so that movements of the roller 65 due to varying tension of the web cause compensating adjustments of the pressure of the belts 50 upon the roll 10. Means are also provided for keeping the belts in operative engagement with the roll 10 as its diameter decreases and these means also serve to produce large changes in the braking force under abnormal conditions such as the breaking of the web. These means comprise a reversible motor 85 adapted to rotate the shaft 81 to increase or decrease the pressure of the belts 50. The motor is normally adapted to be controlled automatically by comparatively large movements of the pilot roller 65 by means of a switch 87 operated by a rod 88 connected to the adjacent lever 72. The switch 87 comprises fixed contacts 89, 90, 92, Fig. 5, connected to the mains 91, 93 through a switch 102, and movable contacts 96, 97 carried by the rod 88 and connected to the motor 85. To prevent the motor 85 from being operated by small movements of the roller 65, the contact 97 is loose on the rod 88 and is operated, with lost motion, by pins 99, 100 carried by the rod. The motor 85 is also connected to the mains 91, 93 through a reversing switch 103 and the switch 102 to allow of manual control independently of the roller 65. The roll 10 is carried by arms 16 fixed to a shaft 40 which may be turned to raise and lower the arms by a segment 33 and worm 28 operated by a handle 22 through gearing 24, 27. In a modification, the lower ends of the belts are secured to a fixed shaft and the motor 85 is connected through gearing, such as the worm gearing 28, 33, to the shaft carrying the roll supporting arms so that the roll is moved bodily to increase or decrease the pressure between the roll and the belts. The upward movement of the roll is limited by causing a part moving therewith to open a switch in the motor circuit. A single pilot roller and switch 87 may be used to control two rolls from which the web is fed alternately, each roll being provided with its own controlling motor 85 and a switch being provided to connect the switch 87 to the particular motor 85 in use. The roll 10 can be adjusted axially for side register of the web by means of a nut provided with an integral hand-wheel 46, Fig. 1, mounted on the threaded extremity of the shaft 40 and prevented from moving axially.